Non-equilibrium dynamical phases of the two-atom Dicke model

M.A. Panzarella, Franco Persico

Sebastian Fuchs, Joachim Ankerhold, M. P. Blencowe +1 more

Abstract The dynamics of the Dicke model, which describes the interaction of N two-level atoms with a resonant field mode, is studied in the presence of dissipation and in strong non-equilibrium for a moderate number of atoms. Starting from a highly excited state, it is investigated to what extent signatures of superradient phenomena known from the thermodynamic limit , namely, superradiant light emission and atom-field correlations characteristic for the superradiant phase, appear on transient time scales. Attention is also paid to subtleties of modeling dissipation in the weak coupling limit and to the dynamics in phase space. The latter allows phase space correlators to be defined as indicators for collective behavior on transient time scales. These findings may be of relevance for the realization of Dicke physics with superconducting circuits.

Manish Chaudhary, Rejish Nath, Weibin Li

We study dynamical phase transitions in the generalized dissipative Dicke model in an array of trapped Rydberg ions, where their density-density interactions compete with the collective spin-phonon coupling, laser driving and dissipation. This setting offers a versatile approach to study equilibrium as well as non-equilibrium many-body phenomena, as parameters, such as the Ising interaction, laser-ion and spin-phonon coupling can be tuned. Through analyzing the mean-field phase diagram, we find a variety of distinct phases and the emergence of a tricritical point that are sensitively dependent of the interaction between Rydberg ions. We then study the quantum dynamics for a finite system size and characterize parameter dependent dynamics using the spin average, entropy, and Loschmidt echo. Distinctive signatures of the dynamical phases, such as slow relaxation and metastability, arise near the phase transition. This analysis predicts rich quantum dynamics of the finite system that link to the non-equilibrium mean-field phases. Our study widens the exploration of collective and non-equilibrium phases in Dicke models, and reveals that the Rydberg ion interaction drastically affects the phase diagram and dynamics.

吉睿 JI Rui, 刘妮 LIU Ni, 梁九卿 LIANG Jiu-qing

Kevin C. Stitely, Andrus Giraldo, Bernd Krauskopf +1 more

We investigate the appearance of classical nonlinear dynamics in the non-equilibrium quantum phase transition to superradiance in the unbalanced Dicke model. Specifically, we uncover a variety of dynamical behavior, including hysteresis, superradiant oscillations, and chaos.

G. Compagno, A. Panzarella, Franco Persico